I went with theAir tank pump seems to work fine at 40 psi also replaced the fuel regulator car runs like a champ thank you everybody for helping me find Gremlins. Sent from my iPad using Classic Zcar Club mobile

I talked to z car depot and they said they sell these to a lot of Z owners and it’s a good price. Plus it has a nice filter before the pump. Can’t find anyone to actually tell me what BOSCH unit would work and is available was not copied crap. This is the first pump besides the stock ones. With everything hooked up correctly I got Carly 2PSI with return lines back to the tank if I clamped off I only get 26PSI. Sent from my iPad using Classic Zcar Club mobile

With the aftermarket pump that I had on the car was only giving me 26 PSI there was plenty of fuel at 26 PSI coming to the filter under the hood. Of course 26 PSI is not enough to keep the L6 running correctly. At this point I’m sure I’ve got a bad pump from the supplier, I will return it and get a different pump. Thanking of this one: https://zcardepot.com/catalog/product/view/id/2535/s/electric-fuel-pump-and-filter-combo-bracket-efi/category/349/ Sent from my iPad using Classic Zcar Club mobile

So it is definitely the pump is not pumping up to adequate pressure. I’ve done electrical test with a pump under load and I get less than .02 voltage drop on the positive side and .005 on the negative side. So I’m thinking that BOSCH 69136 would be adequate pump for my 280. Has anyone used the BOSCH 69136. On Amazon for $74 Any feedback would be appreciated. Sent from my iPad using Classic Zcar Club mobile

So the Bosch fuel pump, I spoke of is the Bosch 0580254044 fuel pump, i’ve read they had a lot of the Z guys use this pump.
I’ll check the resistance on the pump tomorrow. Thanks for all your help any other suggestions always welcome.